Safety device for a gyratory rocket missile

ABSTRACT

A safety device for a gyratory rocket missile of the type with a primer support centrifugally pivotable from a safe to an armed position and centrifugally releasable means for securing the support in the safe position, comprises an axially slidable pin urged by a spring to a position locking the securing means in support-securing positon. The two ends of a resilient open loop releasably engage a groove in the pin to hold it in the locking position and, when the pin moves due to an axial acceleration upon firing the missile so as to free the securing means, the ends of the loop come to bear against a shoudler of the pin to prevent return thereof. Once the support regulated by a delay mechanism reaches the armed position, a finger slidably mounted in an outwardly opening radial housing in the primer support moves out of its housing to lock the support in position.

United States Patent 1 [111 3,777,666

Morel 1 Dec. 11, 1973 SAFETY DEVICE FOR A GYRATORY PrimaryExaminer-Samuel W. Engle ROCKET MISSILE Attorney-Jimmy L. Groff et al.

[75] Inventor: Ren Morel, Geneva, Switzerland [73] Assignee: MefinaS.A., Fribourg, Switzerland [57] ABSTRACT A safety device for a gyratoryrocket missile of the [22] Filed: Oct. 28, 1971 type with a primersupport centrifugally pivotable PP 3, 56 from a safe to an armedposition and centrifugally releasable means for securing the support inthe safe position, comprises an axially slidable pin urged by a I F C Ito P o u 7 [30] orelgn Apphca nomy Dam spring to a position locking thesecuring means in sup- NOV. 3, Switzerland port securing positon The twoends of a resilient p loop releasably engage a groove in the pin to holdit in [2%] }LS.CCII. 102/512102/24 the locking position and when the pinmoves due to f g an axial acceleration upon firing the missile so as tol I I free the securing means, the ends of the loop come to bear againsta shoudler of the pin to prevent return [56] References Cited thereof.Once the support regulated by a delay mecha- UNITED STATES PATENTS nismreaches the armed position, a finger slidably 3,465,676 9/1969 Simmen102/80 mounted in an outwardly opening radial housing in the 3,450,049 9Date 102/80 primer support moves out of its housing to lock the McCaslinupport in position 2,789,507 4/1957 Apotheloz 102/80 1 Claim, 3 DrawingFigures Pmmnnnac n 1975 3771.666

INVENTOR TEA Z M065;

ATTORNEY SAFETY DEVICE FOR A GYRATORY ROCKET MISSILE The inventionrelates to a safety device for a gyratory rocket missile.

Rocket missiles provided with a safety device comprising a primersupport movable between a safe position and an armed position under theaction of centrifugal force, and means for securing this support in thesafe position, sensitive to centrifugual force to free the primersupport, are already known. However, in the case of a fall, for exampleduring transport, it can happen that a missile rolls and hence developsa sufficient centrifugal force to cause withdrawal of the said securingdevice.

The object of the present invention is to remedy this drawback.

According to the invention, a safety device for a gyratory rocketmissile comprises a primer support member movable under the action ofcentrifugal force upon gyration of the missile between a safe positionand an armed position; means for releasably securing the support in thesafe position, said securing means being movable under the action ofcentrifugal force upon gyration of the missile from a support-securingposition to a position in which the support is freed; and means forreleasably locking the securing means in the supportsecuring position,said locking means comprising a retaining member slidably mountedparallel to the axis of the missile between a first position in which itlocks the securing means in the support-securing position and a secondposition in which the securing means is freed, and a spring opposingmovement of the locking means from thefirst position to the secondposition upon axial acceleration of the missile.

The accompanying drawings show, schematically and by way of example, apreferred embodiment of safety device according to the invention. In thedrawings:

FIG. 1 is a cross-section taken along line ll of FIG.

FIG. 2 is a schematic plan view, partially in crosssection along linelI--Il of FIG. 1; and

F IG. 3 is an bottom plan view of a detail as seen along line lIl-lll ofFIG. 1.

As shown in the drawings, the safety device comprises a central housing1 defined between transversal plates 2 to 5. Between plates 3 and 4, asupport 6 for a pyrotechnical primer 7 is pivotally mounted about ashaft 8 parallel to the axis of the rocket missile (not shown) in whichthe safety device is fitted. The support 6 has a toothed sector 9 bywhich it meshes with a pinion 10 of a toothed wheel 12 meshing in turnwith a pinion 13 integral with an escapement wheel 11 movement of whichis regularized by a balance 14 oscillably mounted about a shaft 15. Thepivots of the arbors of the escapement wheel 11 and the toothed wheel 12are mounted in bearings provided in the plates 2 and 5, while the pivotsof shaft 15 of the balance 14 are mounted in bearings provided in theplates 4 and 5. Shaft 15 is tubular to allow for passage of either afiring pin .(not shown) or a flame from a primer located forwardly inrelation to the direction of firing of the missile.

As long as the pyrotechnical primer is not brought into alignment withthe channel formed by the tubular shaft 15, detonation cannot takeplace. The primer 7 support 6 must thus be held in its safe position, as

shown in FIG. 2, as long as the missile, which is designed for use witha rifled bore muzzle, has not been fired. For this purpose, a device forsecuring the primer support 6 in its safe position and a device forlocking this securing device are provided.

The securing device is a conventional device comprising a slide piece 16capable of being radially moved in a slideway 17 provided between theplates 2 and 3. Two independently acting springs 18 and 18' act againstthe slide piece 16 to hold it in an advanced or operativesupport-securing position in which its inner end 19 engages in a notch20 of the primer support 6, as shown. This securing device is sensitiveto centrifu gal force and is constructed so as to free the support 6 assoon as rotation of the missile during the trajectory produces acentrifugal force sufiicient to push the slide piece 16 radiallyoutwardly against the action of the springs 18 and 18. It should benoted that the use of two springs for this purpose enhances reliabilityof the device, since it is extremely unlikely that the two springs couldsimultaneously become defective.

The device for locking the above-described securing device comprises aretaining member formed by a pin 21 including an upwardly extending rod28 terminating a cylinder 23 having a flange 30. This flange forms abearing surface for a return spring 24 which holds the retaining memberin the position shown in the drawings, in which position it locks theslide piece 16 in its advanced position.

The lower end of the pin 21 has a recess in the form of a groove 41 inwhich is engaged stop means comprising an elastic element formed by anopen loop 42 of resilient steel wire housed in a recess 45 of the lowerplate 3. The two ends 43 and 44 of this loop 42 are located on oppositesides of the retaining member and, in the position shown, transverselybear against and removably engage in the groove 41 of pin 21 toreleasably hold the retaining member in position.

At rest, the free end of pin 21 passes through a bore 22 in the plate 3and the other end of pin 21 adjacent and fixed to the rod 28 terminateswith a shoulder 46, said latter end passing through a bore 26 in theplate 2. In this rest position, the pin 21 forms a locking stop memberin the path that the slide piece 16 must cover under the effect ofcentrifugal force to disengage from the notch of the primer support 6.

The cylinder 23 is partially engaged by its free end in a bore 27 of theplate 5 and the flange 30 of the cylinder bears against the lower edgeof said bore. The return spring 24, coaxially located about the cylinder23, is supported between the flange 30 and about the upper edge of thebore 26 in the plate 2 so as to hold the pin 21 in its rest or lockingposition.

When the shot is fired, the axial acceleration is sufficient to causedisplacement of the pin 21 until its shoulder 46 is located below theends 43 and 44 of the loop 42. These ends elastically grip against therod 28 and thus prevent return of the retaining member 21, under theaction of the spring 24, to its initial position. Hence, the retainingmember is held in a position enabling radial outward movement of theslide piece 16 under the action of centrifugal force. The slide piece 16can thus free the primer support 6 as soon as the speed of rotation ofthe projectile reaches a certain value, even if the axial accelerationhas dropped to a value which is less than that which was required todisplace the retaining member against the action of the spring 24.

Because the part 6a of the support 6 is heavier than its part 6bcarrying the primer 7, once freed the support 6 pivots abouts its shaft8 in the counterclock-wise direction, looking at FIG. 2. However, thispivotal movement is slowed by the timer mechanism l-14 in a knownmanner, the toothed sector 9 of the support 6 meshing with the pinion ofthe toothed wheel 12 to limit the rate of movement of the support 6 tothe speed permitted by the escapement device 11, 14.

It is thus possible to delay the action of movement of the primersupport 6 from the same position into the armed position, in which theprimer 7 is located under the channel formed by the tubular shaft 15 ofbalance 14, until the missile has covered a part of its trajectory. Thisavoids any risk of premature detonation, for example if the missileshould hit an object located in the immediate neighbourhood of themuzzle.

Once the support 6 is located in the armed position, it is held in thisposition by a slidable finger 29 engaged at rest in an outwardly openingradial housing 31 in the support 6 and normally prevented from movingout by hearing against a side wall of the plate 2. When the support 6reaches the armed position, the finger 29 no longer faces the side wallof plate 2 and, under the action of the centrifugal force produced byrotation of the missile, moves radially outwardly so that its outer endcomes into place behind a shoulder 32 of the plate 2.

Numerous modifications of details can be made to the describedembodiment of safety device. The springs 18 and 18 could, for example,be eliminated in a simplified type of missile. The means for holding theretaining member in its unlocking position could be formed by elementsother than a loop 42, for example known types of pawl or notch devices.

l claim:

1. In a safety device for a gyratory rocket missile, said devicecomprising a primer support member movable under the action ofcentrifugal force upon gyration of the missile between a safe positionand an armed position, means for releasably securing the support in thesafe position, said securing means being movable under the action ofcentrifugal force upon gyration of the missile from a support-securingposition to a position in which the support is freed, the improvementcomprising means for releasably locking the securing means in thesupport-securing position, said locking means comprising a retainingmember slidably mounted parallel to the axis of the missile between afirst position in which it locks the securing means in thesupport-securing position and a second position in which the securingmeans is freed, a spring opposing movement of the locking means from thefirst position to the second position upon axial acceleration of themissile, stop means for holding said retaining member in the secondposition, said stop means comprising an elastic element bearingtransversely against the retaining member, said elastic element beingremovably engaged in a recess in the retaining member when the retainingmember is in the first position, said elastic element comprising an opentwo-ended loop of resilient wire, the two ends of said loop beingdisposed on opposite sides of the retaining member, said retainingmember comprising a cylindrical pin having a peripheral groove formingsaid recess, and a rod of lesser diameter than said pin extending froman end of said pin and forming a shoulder therewith, said elasticelement engaging against said shoulder when the retaining member is inthe second position.

1. In a safety device for a gyratory rocket missile, said device comprising a primer support member movable under the action of centrifugal force upon gyration of the missile between a safe position and an armed position, means for releasably securing the support in the safe position, said securing means being movable under the action of centrifugal force upon gyration of the missile from a support-securing position to a position in which the support is freed, the improvement comprising means for releasably locking the securing means in the support-securing position, said locking means comprising a retaining member slidably mounted parallel to the axis of the missile between a first position in which it locks the securing means in the support-securing position and a second position in which the securing means is freed, a spring opposing movement of the locking means from the first position to the second position upon axial acceleration of the missile, stop means for holding said retaining member in the second position, said stop means comprising an elastic element bearing transversely against the retaining member, said elastic element being removably engaged in a recess in the retaining member when the retaining member is in the first position, said elastic element comprising an open twoended loop of resilient wire, the two ends of said loop being disposed on opposite sides of the retaining member, said retaining member comprising a cylindrical pin having a peripheral groove forming said recess, and a rod of lesser diameter than said pin extending from an end of said pin and forming a shoulder therewith, said elastic element engaging against said shoulder when the retaining member is in the second position. 